I've just built a new Haswell rig with a Z87-Deluxe motherboard, and wanted to share what I've discovered about its fan control abilities. This is info I wanted when researching the build but couldn't find anywhere, so hopefully it'll be useful to others. I apologize for the epic length, but there's actually a lot to cover.

First off, watch out for the chassis fan headers, they're not what they seem. This board has 6 fan headers: CPU_FAN, CPU_OPT, and CHA_FAN 1-4. All of them look like normal 4-pin fan headers, but CHA_FAN 1-4 are *not* true 4-pin PWM fan headers. They don't provide any PWM control capability, and in fact act mostly like 3-pin fan headers, controlling all fans, whether 3 or 4 pin, using 3-pin style voltage control. The 4th pin, which should be used to control 4-pin fan speeds while the motor power stays at +12V, is instead hardwired for a constant 100% duty cycle PWM signal (fixed +5V). 4-pin fans will see this PWM signal and always run at full throttle, while the motor power is adjusted 3-pin style to control the actual speed resulting from that full throttle. 3-pin fans will work with these headers as if they were plain old normal 3-pin fan headers.

You can get a clue about this weirdness from the pinout diagrams for the fan headers in the user's manual. The 4th pin for the CPU_FAN and CPU_OPT headers is labeled as "CPU fan PWM", but for the CHA_FAN headers is instead labeled as "+5V". In the PWM fan control signalling scheme, a fixed, unmodulated +5V PWM line is just a hardwired constant full speed 100% duty cycle command. But I don't see the point of including it; PWM fans already default to constant full speed when plugged into standard 3-pin fan headers (leaving their 4th pin unconnected) anyway. This is just a tricksy way to make a 3-pin header look like a 4-pin header without really being one.

Why did ASUS go to the trouble of making fake 4-pin headers, when normal 3-pin headers would have worked just as well? It's not helpful, it just causes confusion. When someone plugs a 4-pin PWM fan into a standard-looking 4-pin fan header, they're going to naturally assume the fan will be controlled via PWM. If you plug a 4-pin fan into a 3-pin header, at least you know up front that you're sacrificing the fan's PWM ability and using it as a 3-pin fan. It's almost like ASUS is actively trying to conceal the fact that PWM fans aren't really supported and will instead be run in 3-pin mode.

"Who cares?" many of you are probably thinking by now. After all, both kinds of fans do end up speed controlled (in a Clintonian "it depends on what the meaning of 'control' is" kind of way). But PWM-controlled fans behave differently than voltage-controlled fans, especially at low speeds. Often a PWM fan will start reliably at and hold a lower RPM with PWM than with voltage control. In my case, low-speed behavior was critical; I especially wanted to make sure that my fans would run at a very low RPM and be totally silent when the PC was at idle or low loads, which is really most of the time, and then ramp up to audible speeds only at higher loads, when I'm probably gaming and won't care anyway. For instance, I've got Noctua NF-A15 fans that will run dead silent at about 220 RPM at their minimum 18% PWM duty cycle. But if you ignore the PWM and use voltage control instead, they don't start until about 6.2 volts (52%), at around 675 RPM, which is not quiet enough for me when I'm coding at 3 AM. I ended up solving the problem by daisy-chaining the case fans off of the CPU_OPT header, but I still don't appreciate the misleading design.

Also, in line with that higher starting voltage issue, ASUS enforces a minimum 60% voltage limit (7.2V) on voltage-controlled fans in the BIOS, while it allows a much more useful 20% minimum PWM duty cycle. This isn't a big issue for Windows users, since the Fan Xpert 2 software can override the BIOS limits and tailor them to your fan's actual abilities, but non-Windows users are stuck. For me, 60% is more like the *maximum* I'd ever actually want, during heavy but non-benchmarking usage, so having it as the minimum would really suck.

By the way, I don't think these pseudo-4-pin headers are unique to this board. I spot-checked a few other ASUS Z87 and Z77 board's manuals and saw the same "+5V" tag on some of their fan pinouts. And I'm pretty sure I've seen some forum posts in the past that mentioned PWM fans being controlled as 3-pin fans. Be alert.

OK, so enough ranting about the chassis fan headers. The CPU_FAN header is very different. It really does control both 3-pin and 4-pin fans, using voltage control for 3-pins and PWM for 4-pins. It manages this using a simple but clever trick that I can't believe nobody else has thought of until now. On the edge of the CPU_FAN header, there's a little detector switch that gets triggered when you plug in a 4-pin fan, pushed by the extra connector width, letting the fan controller know to use the PWM signal line instead of adjusting the voltage. Strangely, this cool feature is hardly mentioned anywhere except for a small un-commented drawing by the fan pinouts and a terse note on the manual's specs page saying the "CPU Fan connector supports both 3-pin (DC mode) and 4-pin (PWM mode)". Tellingly, it does not say that about the chassis fan connectors. From photos, it looks like this new CPU fan type detection switch is included on all ASUS' Z87 boards except the most stripped-down -C and -K models.

And lastly, the CPU_OPT header is basically just a passive copy of whatever's being sent to the CPU_FAN header, and can't be separately controlled. If CPU_FAN is in PWM mode, the same PWM signal is sent by CPU_OPT. If CPU_FAN is in voltage control mode, the same voltage is supplied by CPU_OPT. But what if you plug in different fan types? Probably not very useful. If you have a 4-pin in CPU_FAN being controlled with PWM, a 3-pin in CPU_OPT will just see the typical constant 12V of any 3-pin fan on a (normal) 4-pin header and run flat out. And if you have a 3-pin in CPU_FAN being controlled by voltage, a 4-pin in CPU_OPT will confusingly run even slower than the reduced voltage should normally make it; it looks like the PWM signal still gets sent, *along with* the reduced voltage, so 100% is still full speed, but 70% becomes 70% duty cycle of the 70% voltage speed, for a net 49% actual speed. Strange.

So that's the hardware, now the software. At the BIOS level things are pretty standard. There are separate Q-Fan controls for all the fan headers except CPU_OPT, and they mostly work like in previous ASUS boards, with Silent, Standard, Turbo, and Manual control curves. One thing worth mentioning is that since the chassis fan headers are voltage controlled, their minimum speed is forced to 60% (Augh!), but that can be overridden in Windows using Fan Xpert 2 according to your fan's actual abilities. The chassis fans can only respond to the CPU temperature, unfortunately.

For the CPU_FAN header, the controls are a bit more complicated. Instead of just Enabled, you can choose Auto or Advanced. Auto really means "force the header into 4-pin PWM mode", and Advanced really means "detect the fan type with the nifty fan header switch" (which sounds more like Auto to me, but whatever). In Auto (4-pin) mode, the CPU fan profiles use a reasonable minimum 20% duty cycle instead of the 60% minimum voltage of the chassis fans. But in Advanced (detect) mode there's a big problem: since ASUS wants to enforce the 60% minimum speed with voltage-controlled fans, they just always force the 60% minimum for Advanced mode, without caring what kind of fan is or will be actually plugged in, just in case you end up with a 3-pin fan there. So if you do plug in a 4-pin fan while the BIOS is set to Advanced mode, it gets stuck with the 60% minimum anyway. Which means you'll probably want to select Auto mode whenever using 4-pin fans, which means you'll only select Advanced mode when using 3-pin fans, which really kind of defeats the whole purpose of the nifty fan header detection switch. If you end up making a manual BIOS setting according to the fan type anyway, they might as well have just had a simple 3-pin/4-pin mode BIOS setting and skipped the whole hardware switch thing entirely. Sigh.

If you're not running Windows, that's it; the fans keep running according to your BIOS settings until you shut down. But if you run Windows, ASUS' Fan Xpert 2 software can take over control of the fans, giving extra flexibility. And it looks like Fan Xpert 2 is now standard with all these new Z87 boards, so no more discrimination with lesser "Fan Xpert but not 2" versions for the cheaper boards.

Here's how I think the BIOS/Fan Xpert handoff works: I believe the fans are actually controlled by an independant chip on the motherboard, not by any running software (to prevent overheating if the PC locks up, which would freeze any control software). When you boot the PC, the BIOS loads its saved fan settings into the fan control chip, and that sets their behavior until Windows is loaded. When Windows boots, it starts the ASUS Fan Control Service daemon, which then loads your last applied Fan Xpert 2 settings into the controller chip to override the initial BIOS settings. This happens shortly after Windows starts, before you even log in. If you then later use Fan Xpert 2 to apply a new fan profile, that immediately gets loaded into the control chip, and also becomes the "current" settings for that fan to be re-applied by the Fan Service the next time Windows is started. The Fan Xpert settings aren't written to the BIOS, they're only in effect while Windows is running.

That matches the behavior I see, anyway. If you set the fans to one speed in BIOS and another in Fan Xpert, you can clearly hear how the PC boots using the BIOS speed and then shifts to the Fan Xpert speed as soon as Windows comes up, and see your last settings already in effect when you go into Fan Xpert. And if you kill the AI Suite app and stop the Fan Service, the fans continue to be actively controlled even without any fan-related software running. If you completely uninstalled AI Suite III, including the Fan Service daemon, I think your PC would just use the BIOS settings forever, but I haven't actually tried it.

As far as Fan Xpert 2 itself goes, that's already been pretty well described in various reviews, and this is already way too long, so I won't describe all that again. The main point here is that Fan Xpert 2 will test your fans to determine their actual minimum speeds, and tailor the fan control curves to fit. These control curves will completely override any BIOS settings and their hardcoded limits, so that you can use the fan's full range.

Also, I've noticed one small difference from what I've read in reviews; when setting a custom fan profile, previous versions of Fan Xpert 2 set the minimum allowed fan speed to the power required to start the fan, which is usually higher than the minimum speed the fan can be reduced to without stopping once it's spinning (for 3-pin fans, anyway). With this version, it now sets the minimum allowed speed in the profile to the minimum reducible speed. This change might let you run fans at a significantly lower speed than before, and it shouldn't really cause any problems; worst case, if a fan doesn't start because the temp is too low at first, the temp will just rise until the corresponding fan speed hits the starting value, and then the fan will kick in and cool back down to the lower speed while still running. Or you could avoid that by just making sure the BIOS settings will have the fan spinning before Windows starts and takes over with the lower minimum.

Overall the software seems pretty solid, and I haven't had any trouble with BIOS/Fan Xpert conflicts, erratic control, or failures to reload prior settings. I think they've fixed the bugs I've seen reported with earlier versions, and there should be no need to disable BIOS Q-Fan control to use Fan Xpert, as some have said they had to do before. I have Q-Fan set to Silent to avoid making the fans start out loud when rebooting, and then custom fan curves once in Windows.

That's it for the provided software. What about SpeedFan? While I have some hopes for eventually using that to let the case fans take the GPU temps into account, for now, the latest v4.49 doesn't support the Z87-Deluxe well at all. It doesn't see any fan control or fan speed chips, or the system voltages, only temperatures. And for some reason it's reading my 4770K's core temps wrong, showing about half the values seen in CoreTemp or RealTemp. I'm sure it'll eventually be updated, but it may take a long time with the huge flood of new boards just released. Plus, the new CPU_FAN header switch might take some extra work to handle.

And finally, a non-fan note for any prospective Z87-Deluxe buyers who might be wondering: no, the extra 2-digit Q-Code readout on the board doesn't do anything (yet?). ASUS calls the whole thing a 4-digit Q-Code, not two separate displays, but the only codes defined are all still 2 digits long, so the first 2 always read 00. I'd had some hopes that it would display temps or something (after all, ASUS must have had *some* reason for adding it), but no. They should really just make an API for setting the values in software, so apps could make them display temps or fan speeds or network traffic or something useful. Right now, once your system has booted into the OS and is running OK, the Q-Code display is pretty much wasted.

Thanks for this. I am starting to play with a Z87-A and I'll keep these observations in mind as I progress down ASUS' maddening rabbit hole.

I would kill for a software-managed PCIe fan controller with 5-6 fan headers. I've given up on motherboard vendors... I don't think any of them can get their sh*t together in the fan control department.

I couldn't find anything to help with the fan setup on my Z87-PLUS until I found you're post, glad I did as I was about to replace my standard Noctua case fans with PWM ones, I'm going to move them all around later, hopefully ASUS will allow us to change the minimum duty cycle in a BIOS update soon.

Pretty much what i have experienced with my GeneZ IV with fanXpert1 just i had more restrictions from the bios on case fans that i couldn't overwrite, there were a lot of revisions and some users said they could some couldnt, i just got tired of the noise and grab a Zalman Fanmate2 and undervolted my frontal case fan. Personally im about to upgrade to GENE VI (on my way but on a boat), hopping Asus Suite III and fanXpert2 will help me do what i wanted from my initial setup.

I still think Asus has the best control, i just did a build with MSI and still very nice, but their software is very lacking, i couldn't even control well TY141, so i had to do it from bios and has very few tweaks, still manage to get it to a very good performance and noise level, but no where near what i want for my personal pc.

Asus mobos and FanXpert2 has its limitations as you very well posted it, specially the case fan headers limitation on pwm fans, personally i think its easy to work around this limitation by getting 3pin fans that like undervolting and that go low, for example on 120mm fans, Noiseblocker M12-S1 or Scythe Gentle Typhoons GT12, and on 140mm you have Antec TrueQuiet 140, all of those were reviewed by SPCR even ran on Asus mobo with FanXpert2. The PWM fan headers are much more flexible from bios or fanxpert, as you pointed on your write up, so here you got a lot of choices, fans like Scythe Slipstream PWM are really nice being able to drop them very low on this headers. Personally im still waiting for the new Noctua NH-D15 with the AP15 or Thermalright HR-22 with the TY150 for a future cooler =).

I was going to do with Fractal Design Define R4 + Maxiumus VI Hero for the haswell build, but Asus disappointed me with the new GTX780 DCUII, so i erase my plans and went again with TJ08-E a stock GTX780 + Accelero III, same combo as i have now and just hopping on the Gene VI and fanXpert2 to deal with my FM181 dynamically, and ill be set till skylake.

Overall i think Asus/FanXpert does offer more control than other mobos, and i do recommend them over most, but i do agree that would be great if a lot of this limitations were corrected for the future, maybe with FanXpert3 =)

Interesting findings about the CPU_FAN and CPU_OPT headers on your Z87 board. I have a 990FX Sabertooth (rev.1) and those 2 headers do NOT control 3-pin non-PWM fans using FanXpert2. I have a Coolermaster Hyper212+ with 2x Scythe Gentle Typhoons (1450rpm, 3-pin) in push+pull config and it does not change the speed always running at 100%. The other chassis headers can control 3-pin fans (a bunch of 1200rpm Scythe Slipstreams).

I tried searching for info on that and only came across a few posts mentioning that on some Asus boards, the CPU_FAN and CPU_OPT can only alter speed on 4-pin PWM fans, not 3-pin fans. I guess technically I could run those GTs on the chassis headers, but then the low rpm CPU fan warning won't work. I ended up digging up my old Zalman MFC-1 fan controller and hooking up all my fans to that. The translucent blue front plate and bright blue LEDs are a bit too bling, but I usually keep the door on my P183 closed so it doesn't matter too much. I also tried to find some PWM Gentle Typhoons, but they don't make a low-medium speed PWM GT. The only PWM GT models (that you have to hack to get PWM) start at 3000rpm, which is way too loud.

I also noticted that SPCR uses a custom voltage controller in their 3-pin fan testing with the P8Z77V-Pro instead of the 4-pin CPU fan headers.

I think what amazes (and frustrates) me most about all this fan behavior stuff is that it's still even an issue at all. This isn't rocket science, it's not like PC fans are some bleeding-edge new tech. They're trivially simple, and you'd think that some dirt-cheap totally standardized solution for the whole thing would have been created years ago and long since been adopted by everybody.

How about a simple 4-pin header control chip where you load the desired RPM, and it first tries to sync the fan's RPM by signaling with PWM on the 4th pin, and if the RPM doesn't change, then switches to adjusting the fan motor voltage instead? And for the advanced chip you add temperature input, and load a few RPM vs. temperature points to describe a curve. They could have easily done that back in the days of my Atari 800 if they'd bothered to, let alone by the time PCs actually needed fan control.

4-5 GHz CPUs, with GPUs built in? OK. Massively intricate chipsets with SATA, USB, PCIe, and other incredibly complex stuff all crammed together and working in perfectly synchronized harmony? Sure. Precise but flexible control of a 4-wire fan circuit? Whoa, that's too damned hard.

Instead the motherboard makers give us this half-assed thrashing around for year after year, trying every possible combination of options so that you never know from one board to the next (or even one fan header on a given board to the next!) what weird variations you'll see. It's silly and frustrating and stupid. Argh.

I'm thinking about upgrading to Haswell and a Z87 (mATX) mb. Good I found your writing, it makes me think a bit, and rises a few questions (hope I'm not steering the discussion away / hijacking a thread ):

(for the OP): In BIOS, CPU fan and CPU_OPT are wired up in this weird way in parallel. After bootup, can you control them separately via FanXpert 2 in Windows?

Is there a comparison for the different manufacturers BIOS-based FAN controls (i.e. without windows software)?

From this thread, I gather that all of the mb manufacturers BIOS-based fan controls suck (more or less), but ASUS sucking the least. Being a Linux user, fan control with windows software is useless to me.

For cleanness sake, I would prefer to control the FAN's via the MB, providing it can be made to work (no need for switches / cludges - also I have limited space in the case, especially for mounting controls outside). The other option of course being bypassing the MB connectors and running fans by hand (12v/7v/5v or with a resistor / fanmate / whatever).

In case the controls are supported (by lm_sensors) I guess I could make a script to control them - but, I'm scared my script will hang / crash / do something stupid . But, the same could happen in Windows - imagine a runaway process keeping the CPU at 100%, and the fan controlling software becoming unresponsive. In such a case -

In general, does the MB BIOS's have a fall-back (temperature setting), when they will ramp up the speed (even if the software dies / has not set a higher RPM when a certain temperature is reached)?. I understand rhuebner believes that the FanXpert2 loads the settings to a chip on the MB.

But, what about if there's no such instructions uploaded to the chip at all (instead, the FAN's set to run at, say 20% RPM manually)?

Of course, there's the fall-back temperature that will trigger a shutdown, which I don't think can be overriden

I believe most fans could be controlled with the help of lm_sensors in Linux in theory. Which bring me to a few other questions (hope some other Linux-users could answer).

AFAIK, there's no ready-made fan-controlling daemons available (I don't mind, but on the other hand neither need a GUI). or are there?

But, even if there is, there could be compatibility problems with 1) reading the FAN RPM, 2) reading the temperatures and 3) PWM / voltage controls for the FAN's, as all of the previous are controlled by more or less proprietary chips, which differ from mb to mb.

Is there a database, of which MB's temperature / fan speed monitoring, and fan speed setting are supported in Linux?

(for the OP): In BIOS, CPU fan and CPU_OPT are wired up in this weird way in parallel. After bootup, can you control them separately via FanXpert 2 in Windows?

Not the OP, but if its like my GENE Z, the CPU/OPT header are mirrors, from BIOS you only see CPU header, you can read the rpms of both headers though, but you cant control the OPT header, its more meant for twin fan coolers like Twin towers (Silver arrow, NH-D14, Genesis, or any pull push setup) or a watecooling where you have fan and pump. You can see on my signature, MICROMI build you will find HardwareInfo screenshot where at the bottom you can see both fans around 900rpm, both are Noiseblockers PLPS PWM 120mm fans, and one is connected to the CPU header and the other OPT header, for me its not a big deal, personally i like it as in TJ08-E + HR02 the fans end up like push pull setup.

Wild Penguin wrote:

Is there a comparison for the different manufacturers BIOS-based FAN controls (i.e. without windows software)?

Not that i know off. ASUS imo has the best Fan control software (as long as you do know what fans you can run where), but for pure bios i dont like ASUS, first only the CPU header can be allowed below 60% (all chasis fans cant go below that), for CPU its 20%, and even then i couldnt go that low with my PLPS without fanxpert. For BIOS only no software, i like more MSI (at least on Z77 havent tried Z87 bios yet), the MSI has target % and minimum RPMs, i just did a build for friend on MSI Z77, and i placed a minimum of 40% (or around there, if i went lower the fan would tick) and a target CPU temp of 55C (you can vary this number), i chose that point mostly cause i didnt want the fan to ramp up before reaching that, that made the PC virtually indauble at idle, its not all nice on the MSI though, the chassis headers also has limitations like ASUS, i couldnt get Scythe Slipstream PWM below 800rpm (this fan can drop to 300rpm easily with intel mobo bios), this was unnecessary so i decided to use only the CPU header to be able to use a lower %, i just grabbed a Akasa Flexa FP5 PWM 5-Way Splitter - Smart Fan Cable (AK-CBFA03-45) and connected 4 fans to it (2 frontal 120mm fans 1 back 120mm fan and the TY141 from the HR02 macho, all PWM), and now all its controlled by the BIOS, ended up pretty nice setup to be only controlled by pure bios. I think MSI is much better than ASUS for pure bios control so thats what i would recommend you for Linux, but in windows i would take Asus over MSI, so much control its what has me only looking into asus for the time bieng.

Btw if you fear to much cables on the akasa, dont worry, i hide all mine behind the motherboard tray, if you see the PC is clean, and its safe to run the 5 fans as it doesnt draw the power from the motherboard header, only the PWM signal, the power is deliver by the Molex connector. As a final recommendation, get PWM fans that can be dropped really low, as a suggestion Scythe Slispream 120mm PWM SY1225SL12LM-P are cheap and they have a very good range of operation via PWM (300-1300rpm), so you can play around with the MSI BIOS settings. Atm i have mi HTPCMI build (check sig) with very similar to Scythe PWMs and i can run all of them around 300rpm in an intel mobo via bios, if you wish to read from SPCR about the slipstream check Scythe Mugen-2 CPU Cooler, the only bad news is that next to impossible to get them in the US with how Scythe distribution is in the US.

...I believe most fans could be controlled with the help of lm_sensors in Linux in theory. Which bring me to a few other questions (hope some other Linux-users could answer).

AFAIK, there's no ready-made fan-controlling daemons available (I don't mind, but on the other hand neither need a GUI). or are there?

But, even if there is, there could be compatibility problems with 1) reading the FAN RPM, 2) reading the temperatures and 3) PWM / voltage controls for the FAN's, as all of the previous are controlled by more or less proprietary chips, which differ from mb to mb.

Is there a database, of which MB's temperature / fan speed monitoring, and fan speed setting are supported in Linux?

lm_sensors already has a fan control script that can be setup to control all of your fans if drivers are available which will be the case for most of these devices.

lm-sensors has a DB of the supported motherboard devices. Have a look at their web site.

lm_sensors already has a fan control script that can be setup to control all of your fans if drivers are available which will be the case for most of these devices.

I fad forgotten this. The script is called "fancontrol" . I have used to use it years ago on an older setup, but didn't need it anymore since my current HTPC is quiet enouh with Gigabyte's BIOS's control (there isn't really any options on this GA-MA78GM-S2H, apart from disabling it, but it works).

For those interested, basically, the script lets you choose one temperature sensor to control one (or probably even more) PWM (or probably voltage-controlled, if the MB has an option for it and is supported). It adjusts the PWM valua linearly according to the temperature, and helps you find the minimum values when your fan starts and stop.

hvengel wrote:

lm-sensors has a DB of the supported motherboard devices. Have a look at their web site.

I had forgotten this, too. However, their database only lists sensor chips (see their FAQ). Hunting down via Google, which chip is on a said motherboard, is tedious, and I haven't yet decided which motherboard I'm going to buy. But I will take Abula's remarks into account when choosing one.

The OP says consistently that the 3-pin mode is voltage vs PWM, but I haven't seen an ASUS board since the old WS P4 series where that is actually the case. Instead, the third pin is PWM +12 (ie, a 12V variable-width square wave), not a smooth analog variable voltage. Maybe someone with an oscilloscope can clarify...

BTW, this whole PWM vs voltage thing keeps getting confused. In a standard 4-pin setup (CPU header on all Intel compatible boards), pin 3 is constant +12, and pin 4 is a variable-width +5 square wave control signal, with the motor on-off logic residing inside the fan. In a modern 3-pin setup, pin 3 is +12, modulated as a variable-width square wave, and the fan is just a passive motor.

Based on the OP, it looks like ASUS has decided to mess with the Intel CPU header standard. What fun.

Yeah, you're probably right about the "voltage controlled" mode actually being implemented by PWMing the +12v line. I was just calling it that to differentiate the "control the motor speed by messing with the voltage supplied to it" style vs "give it 12v and a separate logic signal to tell it what speed to put out". In the end, the actual goal of PWMing the motor power that way is still to control its net effective voltage (averaged over time), they just use PWM as a cheaper and easier way to do that than including a proper DC-to-DC converter circuit.

Which is just yet more screwing around by the mobo makers instead of doing it right, and can cause its own problems with fans that click or buzz when you fast-stutter their power that way (literally jerking them around). In my previous rig I used an Aquaero LT controller because of that, since it has true linear regulators (with optional heatsinks, or even a water block!), but this time I wanted something simpler and less cluttered.

Since 4-pin fans have become well known as "PWM fans", you need some other way to refer to the other kind. And since with 4-pin fans the PWM signal is the main point, but with 3-pin fans any PWM that might happen to be involved in a particular implementation is really just a side-effect of how they chose to go about messing with the final net voltage, I think it still makes sense to call 3-pin fans "voltage controlled" instead. This is all confusing enough to the 90% who don't know or care about these details; telling them "it's all PWM, really" wouldn't be that helpful, even when it's true.

As for ASUS' new CPU header design, I think it's great, and a good step towards creating a true universal fan header that really works right with both kinds of fans. True, they're messing with the 4-pin header spec, but in a way that's totally backwards compatible. A 4-pin fan plugged into it sees exactly what it should, and a 3-pin fan also sees what it should (except that as you noted the voltage is probably choppy and not properly regulated). Now if they'd just fix the BIOS control so that it was really automatic (if you *must* have a minimum 60% voltage for 3-pin, then also provide a separate PWM minimum value and have it automatically use the right one), and make all of their fan headers that style instead of leaving the rest screwed up, and maybe even put in some halfway-decent DC-DC regulation for true voltage control...

It's not like they can't figure this stuff out. Apparently, they just can't be bothered, or maybe it costs 20 cents more per board to do it right, and they don't think anyone cares.

I have Z87-Pro with 4770 and Zalman cnps14x and also ran into this weirdness. In auto mode, motherboard couldn't really control my fan (was only able to go somewhere between 1150 to 1200 rpm). So I've switched it to Advanced and set the following settings in bios:

Max Temp: 70Max %: 60%Min temp: 45min %: 60%

Here is where it gets a little weird: when I boot into windows, Fan Xpert 2 shows the following and thankfully CPU fan is completely off until temps are over 50C.

Not sure why it works, or how it works but it works very nicely. Only think that I did differently is typed "10" for "Min %" in bios which automatically got changed to 60.... maybe it did take 10 after all.

I think this is the standard only 1 true PWM fan that can be controlled via the PWM signal, the rest even if they are 4pin, they are voltage controlled.

On asus usually there is CPU_FAN and CPU_OPT, but only CPU_FAN is controllable via PWM, the CPU_OPT is just a mirror, kinda like Y splitter of the CPU_FAN. On MSI i have my doubts if its just a mirror or if they are independatly controlled cause there is a BIOS section for CPU_FAN2, on Asus motherboards on pure bios you cant see the CPU_OPT, or maybe its just for monitoring.

Either way on pure BIOS, for me MSI > ASUS, as you can see on the bios above, the restrictions on PWM are very low, 12.5%, 25%, 37.5%.... 100%, i personally tested on a friends Z77GA43, and it works great. On asus it sucks atm, the lowest that they allow on bios is 40%, i have open a petition to asus to request they lower the PWM minimum cycle from 40% to 10%, ASUS Bios fan control request. If asus dont change this on bios, ill be switching to MSI when i move back to ATX.

I've got an Asus Z87-Pro (with BIOS 1405 dated 2013.08.29) that has some peculiar BIOS fan control restrictions, as noted by OP. In my case all my fans (Noiseblocker M12-S2 for chassis fan and a single NH-C14 stock fan) are 3-pin that has a 60% minimum duty cycle, but for the chassis fan the field I cannot set the minimum temperature that defaults to CPU 40 C.

For acoustic reasons (I'm close to the PC with the PC under a table close to a corner) SPCR silent is not silent enough in idle mode. When I close the side panels to my Antec P180 (first version) I get some unpleasant fan noise.

So, Asus FanXprt2 is very nice, if you manage to install it, that is! You must install from the CD as downloads from the support site will not work (hanging, etc) with exactly zero info to the user on lack of progress. When originally installed from the CD you can upgrade using software download. As a software engineer I think this pretty shoddy work.

There is an increase in minimum fan speed going from AI Suite version 1.00.51 that either is a minimum cycle duty or start RPM. Luckily I could downgrade so my CPU fan is at 300 RPM at idle.

I've got an Asus Z87-Pro (with BIOS 1405 dated 2013.08.29) that has some peculiar BIOS fan control restrictions, as noted by OP. In my case all my fans (Noiseblocker M12-S2 for chassis fan and a single NH-C14 stock fan) are 3-pin that has a 60% minimum duty cycle, but for the chassis fan the field I cannot set the minimum temperature that defaults to CPU 40 C.

Yes Bios Fan Control Restrictions imo are way to high, MSI is much lower than ASUS, but on pure software FanXpert2 can overwrite all the bios restrictions. I went away from Asus mostly out of issues with drivers on the realtek 1150 and some issues with Nvidia drivers + AI Suite III. But returning to the bios, i posted a request on ASUS ROG forums asking for a revise bios, but seem the Asus represntatives dont see it the way i do, so is unlikely it will happen, ASUS Bios fan control request, very likely the Asus Maximus IV Gene will be my last Asus motherboard, until they reconsider their BIOS Fan Control, i still recommend them though, as fanXpert imo is still very good, the bad thing is that it comes bundle with a lot of things that i dont use and the way Asus measure temps imo is not correct.

blankus wrote:

So, Asus FanXprt2 is very nice, if you manage to install it, that is! You must install from the CD as downloads from the support site will not work (hanging, etc) with exactly zero info to the user on lack of progress. When originally installed from the CD you can upgrade using software download. As a software engineer I think this pretty shoddy work.

Personally didnt have any issues installing ASUS AI Suite III V1.00.50, and then upgraded to ASUS AI Suite III V1.00.55. But when i tried uninstalling some error appeared, ran the AI Suite III Cleaner and installed the new one, and everything seem to wroked fine, but the AI Suite seems still a little shaddy, like in beta, but FanXpert2 works really well. Personally im more happy with MSI bios fan control, and specially since i dont need extra software, but you do need to carefully chose the PWM fans you will use and only use CPU_FAN1 and CPU_FAN2.

blankus wrote:

There is an increase in minimum fan speed going from AI Suite version 1.00.51 that either is a minimum cycle duty or start RPM. Luckily I could downgrade so my CPU fan is at 300 RPM at idle.

First my thanks to the OP. You probably spent way too much time on this I knew all of this (non-Asus) specific) fan control stuff apart that NON-PWM fans could be controlled by PWM'ing the 12 voltage line. Let's say that it explains a few things I had been noticing about clicking fans...

@Vulcan. I know it has been a month since you asked but I have a Z87 Pro 3 Asrock board. It appears that the 4-pin chassis and CPU headers are are unable to control 3-pin fans. I still have to test the 3-pin CPU header. If you still need to know this, I will get back to you here. Please PM me.

Just want to check if i'm understanding correctly. I'm using a asus z87-c motherboard and thinking of getting a noctua d14 with pwm fans and some nf-a14 pwm case fans, so there is no point in me getting pwm case fans as the only true pwm header is the cpu fan header and all the other fan headers would control the rpm via voltage regulation and i might even have better results using the nf-a14 3 pin instead as pwm may become unstable controlled via voltage regulation instead of pwm line?

Also since the opt cpu fan header just mirrors the main cpu header, would it be a bad idea to get the d14 since it has 2 different fans, a 140 and 120 fan?Is there any fan controllers that i can get that would let my utilize the pwm fans?

This FanXpert2 has a stupid limitation. It does not like standing fans, but they can still be used.

When I buit my new rig, I wanted it to be silent. In my terminology silent means 0dB noise.I have used:- Asus Z87 Plus (because of underclocking possibility and fan control)- i5-4670K (K because of possibility to underclock and undevolt if necessary)- Passive CPU cooler (Nofan CR95), - Passive power supply (Silverstone Nightjar 400W)- Passive Graphics Card (Asus HD7750-DCSL)- Large case with good ventilation (Silverstone TJ04)- SSD hard drive- BluRay R/W (ok ok it is noisy, but only when there is disk in it)

I still have two case fans, but I want them to be just-in-case fans. They should rotate only in extreme conditions.First I made a mistake and I ran the Fan Auto Tuning process. Do not run Fan Autotune if you want silent PC !I did not find, where the fan curves are stored so I had to reinstall AI Suite 3 (yes, it is very difficult to uninstall)

Now I have two low rpm case fans connected to CPU_FAN and CPU_OPT. Without running Autotune I have freedom toset minimum power to 10% (standing fans) up to 60C . Fans start rotating at 65 C (about 30%) and they are runningfull speed at 75 C.

In practice fans are rotating only if I test with CPU Burn. Fans do not start when playing typical games, like GTAIVThere has been no need to underclock the system to keep it silent.

I tried running Fan Xpert 2 on Fan Xpert+ only mobo (P8Z77-M) and everything works great and without problems.

It's a nice step up from Xpert+, that had fixed low limits and didn't actually analyze fans to set the limits (min CPU=20%, min CHA=40%). Now I can set fans to their lowest safe RPM or turn them off, which is great.

You can cheat asus program to get better minimum rpm values, but that doesn't fix the ticking pwm noises (too low and the ticking start or stopping.. tested with noctua A14/A15 PWM)in the fake pwm channels..

I've just now (a year later) switched to speedfan after going to a crossfire setup and wanting to control fan speed off GPU temperatures rather than CPU temperatures as I've no issues cooling my CPU with minimal fan but the GPUs run up to 70c... It is a little tricky to figure out but when you've got it all sorted (with the help of google a couple of times) it works fantastic and my rig runs more quietly than ever (Fan Xpert is rather limited) I am using 4 of my PWM fans off the 3 CHA fan headers and 2 of them off a 3 way PWM splitter in conjunction with the CPU fan. The PWM fans work a lot better under PWM control than they do with varied voltage (My xagmatek XAF-1455 fans run a lot faster on 75% PWM than they do 100% via voltage control- not sure why really) so I was looking for a device that would convert varied voltage into a PWM signal.. but so far no luck. I thought I would add the info I've come across to this thread though, for those who were interested.

I have a M5A99X. The way I have read this thread leads me to conclude that I will not be able to get the ASUS bios to see my chassis fan, correct? Its an Arctic F12 4pin. That means I will only be able to control my CPU speed in Fan Expert?

I have a M5A99X. The way I have read this thread leads me to conclude that I will not be able to get the ASUS bios to see my chassis fan, correct? Its an Arctic F12 4pin. That means I will only be able to control my CPU speed in Fan Expert?

4pin fans can be controlled either voltage or pwm, but in some cases using pwm fan via voltage controlled can result in inestablities, like fanXpert2 can determine a voltage that the fan cant sustain the rpms (this happen to me with 3 different fans, but with others there i had no issue). The reality is that its not a standard thing, its more for you to test and see what happens with your setup. Also artic fans are weird from what i remember, at least some of them like they were an adaptation of a voltage controlled fan into their own PWM implementation, dont take my word for it though, this was a long time ago, not sure how are their fans now a days.

Who is online

Users browsing this forum: No registered users and 2 guests

You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum